System of multifrequency circuits



Nov. 29, 1927.

1,650,655 A. F. ROSE SYSTEM OF MULTIFREQUENCY CIRCUITS Filed Jan. 21, 1924 2 Sheets-Sheet l 45 T 1m? 1 1%; I Mfg 4/ I 6' Z 6' L 42 T W T W T v /d? 9 72 3 of 65: r 2 c J Z4 1 0 g L4 L4 2 5 4 '5 '3 a M :6 M L- M 5 1 5 7 WV T W1;

ATTORNEY Nov. 29, 1927. 1,650,655

A. F. ROSE SYSTEM OF MULTIFREQUENCY CIRCUITS Filed Jan. 21, 1924 2 Sheets-Sheet 2 E g E L f 14 LP 15 F INVENTOR w "H e u e. a i

ARTHUR F. BOSE, E VEST 1301i, NEW) YORK, ASSIG'NOR TO AMERICAN TELE- IPHGNE AND TELEGEAPII COMPANY, A COREGRATIUN OF KEV] YORK.

SYSTEM 01 ETULTEFEEQTJ'ENGY GIBC' UITS.

Application filed January 21, 1924. Serial 110. $87,564:.

The principal object of my invention is to may be as given in the following table, provide a new and improved. method and which is complete for Fig. 1: 1' t f h ta sfer f currents of i 1; i 4 t e I T i L =L =53.21nh. C =.1711mf. particular frequency range irom one cllcuiu e W O n I li n-65.811111. C...O5n9mf. 5 to another. Anot er ob ect or my invention 15:39 9 mh 106111.

i. 7 i rai rine' 111'181 cur- 3 c S 101 2 a i r L =16Amh C,.,=.O85omt. rents between part or one circuit and part of another circuit while keeping voice fre- With these values, the assembly 13 1s a low (f uency currents respectively on each of the pass wa ve filter with its critical frequency 10 two circuits as a whole. Another object of at 3,000 cycles per second; that is, tremy invention is to provide for the transfer quencies below this value WJll be transmitted 60 of currents of a certain frequency range beeither way along the line 11, 12 but he tween a part of one circuit and a part of quencies above this value Wlll be shunted another circuit where these circuits are comout. prised as side circuits in phantom circuits. Another similar line 14, 15 has a similar These and various other objects of my ininterposed lowpass wave filter 16. c5 vention will become apparent on consicerait 15 desired to transmit superposed high tion of a limited number ofspecific embodifrequency carrier currents between the part inents which I have chosen to illustrate in 11 of the line 11, 12 and the part 15 of the the accompanying drawings and describe in line 1a, 15. Accordingly, at 17 and 21 the following specification. It will be un branch circuits are taken off and connected 7o derstood that the invention is defined in the at 20 through two high pass wave filters 18 appended claiins'and that the following deand 19. Each of these high pass filters 18 scription refers more par ticularly to the speor 19 consists of reactances arranged as cific examples which have been chosen for shown inthe drawingand with the values presentation in this specification. given inthe foregoing table. With these is Referring to the drawings Figure 1 is a particular values, the high pass Wave filters diagram of two through circuits with. means 18 and 19 have the critical frequency at to transfer a certain limited frequency range 3,000 cycles per second. of currents between a part of one of these Voice frequency ci'lrrents on the line 11 circuits and a part of the other circuit, Fig."- will not be diverted over the branch couso 2 is a diagram showing two pairs of side cirductor 1? because the high pass filter 18 cults each pair being comprised in a phanwill not transmit them to an appreciable tom circuit with means to transfer currents extent. (in the other hand, these voice freof a particular frequency range between a qucncy currents will be transmitted through part of a side circuit of one pair and a part the low pass filter 13 to the line 12. Simiof a side circuit of the other pair, and Fig. larly, voice frequencycurrents will be con- 8 is a. diagram illustrating a transfer befined to the line 1 1,15. Carrier currents of tween a side circuit of a phantom on the one relatively higher frequency on the line 11 hand and a simple non-phantom circuit on will not be transmitted by the low pass wave the other hand. filter 13 but will be transmitted by the tan- The metallic circuit 11, 12 in Fig. 1 has a dem high pass wave filters 18 and 19 to the low pass filter 13 interposed therein. This part 15 of the line 1 1, 15, and vice versa, low pass filter comprises series and shunt high frequency carrier currents will be reactances arranged as shown in the drawtransmitted from the line 15 to the line 11.

ing. The letters L for inductances and the Vfith the arrangement shown 'in Fig. 1, it 9 letters C for capacities are meant to indiwill be seen that carrier currents can be sucate the same values when they have the perposed on voice frequency circuits and can same subscripts. For example, these values be diverted from a part of one such circuit and 11- another phantom, the phantom en'- 28 being connected at th middle points oi the proper windings respcctire reueatin coils 27 and 2'1.

Tlciagram shows that the part 11 of the side circuit 11, 12 is connected to the part 15 ot the side circuit 1%, 15 through the high pass filters 1.8 and 19, so that 11, 15 coi'istitutes a carrier current circuit. 'ihe low pass filters 13, 3, i6 and 16 are interposed according to the same principles as in 1. Instead 0t connecting the hi h lass filters 18 and 19 as at 20 in 1, I connect them through a 1-to-1 ratio repeating coil 22. Similarly, the part 11 of circuit 11, 12 and the part 15 of circuit 1%, 1.5 connected through the high pass wave filters 1S and 19 and the repeating coil 22. Each of the repeating coils 22 and 22 is shielded with a respective element and 23. These sl saields 23 and 28 are connected together at The explanation for Fig. 1 will be seen to apply for Fig. 2, and in addition, it will here be pointed out that the transformers at 22 and 22 prevent the phantom circuit voice currents from getting across between the phantom circuit 11, 11 and the phanton'i circuit 15, 15. Moreover, the shields 25.3 and 23 with the connector 2i insure against capacity current gettting across these phantom circuits due to the proximity of the windings of the coils 22 and 22. In so "far as there is a capacity effect between these coils, the resulting current will be shunted across at 2 t and will not be transmitted between 11., 11' and 15, 15.

The transformers and 22 are desioned with the proper inuiicdance value so that, as interposed in the line, they do not prcduce substantial. rcfiection eti'ects.

lit will be seen that ll. a pair oi side circuits constituting a phantom ci -cuit passes in proximity to another pair of side circuits constituting a phantom circuit, and it each side circuit and each phantom circuit carries voice frequency currents, then by my invcntion, superposed high frequency carrier currents can be transferred from the parts extending one way of one pair oi side circuits to the parts extending one way of the other pair oi side circuits, and the normal transmission of the Voice currents on the side circuits and the phantom circuits will not be impaired.

shows provision for transferring high frequency carrier currents betwicn one side circuit 11, 12 oi a phantom pair and a simple non-phantom circuit 14., 15. it will be seen that as :lar as it goes the system is subs antially the same as in Fig. This rrangement is useful in eliminating noise from a phantom circuit when the carrier current on one side of the phantom group is transferred to or from a non-phantom circuit. There is no cross-tall: problem involved but the connection of one side of the phantom group through the high pass filters would unbalance the phantom causing noise, and the interposed transformer 22 obviates this disadvantage.

I claim:

1. In combination, two phantom circuits each conun'isinp; a pair of side circuits all adapted for through transmission oi' cur rents of a cer rain frequency range, and means comprising a transformer to transfer currents oi another "frequency range between a side circuit one pair and a side ci cult of the other pair.

2. In combination, two phantom circuits each comprising a pair or side circuits and adapted for through transmission of currents or a certain frequency range, and means comprising a transformer to transfer currents of another frequency range between a part of each side circuit of one pair and a part of a respective side circuit of the other pair.

In combination, two phantom circuits each comprising a pair of side circuits, low pass filters interposed in the respective side circuits, and high pass filters interposed between a part of eac 1 side circuit of one pair and a part of a respective side circuit of the other pair, the connection that comprises the high pass filter also con'iprising a trans- "former.

4. In combination, two phantom circuits each comprising a pair of side circuits, low pass filters interposed in each side circuit, and connections from one part oil. each side circuit oi a pair to a part of a corn-spendlug; side circuit oi the other pair, each such counection comprising two filters rounec I! through a. repeating, coil.

5. In combination, two phantom circuits each comprising a pair oi side circuits, low pass filters interposed in each side circuit, and connections from one part of each side circuit of a pair to a part of a corresponding side circuit of the other pair. each such con-- neetion comprising; two filters connected through a repeating coil, the said repeating coils being shielded and the shields being, couductively connected.

6. in combination, a phantom circuit, conii'irising two side circuits, a sin'iplc circuit, low pass filters across one o't said side circuits and said simple circuit, and a high pass filter connecting said one side circuit on one side 01? its low pass filter to the simple circuit on one side of its low pass filter, this connection that comprises the high pass filter also comprising a transformer.

7. A system of interconnected signal trans-- mittitng lines comprising two complete phantoms, low pass filters interposed in the side circuits of each phantom, cross connections from each side circuit of one phantom on one side of its corresponding low pass filter to a side circuit of the other phantom on one side of its low pass filter, double high pass filters in said cross connections, transformers between the parts of such dou ble high pass filters, and connected shields for the transformers.

In testimony whereof, I have signed my name to this specification this 17th day of ARTHUR F. ROSE.

January, 1924. 

